Figure 3. Position of the axis of the early Miocene equatorial bulge with respect to the hotspot predicted position of the equatorial region, from Knappenberger (2000). The hotspot position is about 2° north of the equatorial position defined by the sediment bulge. The sediment mass accumulation rate was estimated from physical properties of sediments and the distance between seismic reflectors in profiles collected on the EW9709 site survey. The ages of reflectors (20-16.3 Ma) were dated using the Mayer et al. (1985) Neogene equatorial Pacific seismic stratigraphy.